JP2579498B2 - Wafer processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] A wafer processing method for separating chips from a wafer without damaging the semiconductor chip formed on the wafer accurately and separating each chip without damage. In a wafer processing method for cutting a wafer into rectangular chips, a step of fixing the wafer by vertically sandwiching the wafer between an upper plate and a lower plate, a step of cutting the wafer into a lattice via the upper plate, and a process of cutting the lower plate And a step of further dividing the wafer into a lattice in a direction perpendicular to the direction previously divided through the wafer.

[Industrial applications]

The present invention relates to a wafer processing method for separating chips from a wafer without damaging the chips.

[Conventional technology]

FIGS. 5A and 5B are explanatory views of a conventional wafer processing method. In the figure, 31 is a wafer, 32 is a chip, 33 is a table, and 34 is an adhesive tape.

The conventional wafer processing method, as shown in FIG.
An adhesive tape 34 is fixed on the table 33, and the wafer 31 is moved thereon in the direction of arrow D to fix the wafer 31 thereon. Then, as shown in FIG. 3B, each chip 32 was cut by full cutting. The cross-section of the wafer after the cutting is described in the following sixth section.
It is shown in the figures.

[Problems to be solved by the invention]

(A), (b) and (c) of FIG. 6 are cross-sectional views of a wafer showing a conventional problem. In the figure, 32 is a chip, 34 is an adhesive tape, 35 is a pin, 36 is an air pin unit, and 37 is a cut groove.

However, in the conventional method using the above-mentioned adhesive tape, as shown in FIG. 6A, each chip 32 is separated from the wafer from the cross-sectional state of the wafer after full cutting. that time,
As shown in FIG. 6 (b), the chip 32 is pushed up from below by the pin 35. However, since the adhesiveness of the adhesive tape 34 varies, the weak portion is peeled off first and the chip 32 is tilted and lifted. There is a problem that chipping occurs in the portion indicated by.

As shown in FIG. 3C, when the chip 32 is not completely peeled off from the adhesive tape 34 when sucked by the air pin unit 36, the chip 32 is sucked obliquely, and the air pin unit 36 and the portion G in the figure are drawn. Or touch with the next chip 32
And contact at the portion F in FIG.

In addition, the adhesive tape 34 may cause problems such as discoloring of the gold used on the back of the wafer in a short time, chip flying, and misalignment within the collet if the timing of lifting the chip 32 is poor. was there.

Accordingly, it is an object of the present invention to accurately cut a semiconductor chip formed on a wafer and to surely separate each chip without damaging it.

[Means for solving the problem]

The above problem is that, in a wafer processing method for cutting a wafer into rectangular chips, a step of fixing the wafer by sandwiching the wafer between upper and lower plates from above and below, and a step of cutting the wafer into a lattice via the upper surface plate, A step of further cutting the wafer into a lattice in a direction orthogonal to the direction of the first cut through the lower surface plate.

[Action]

That is, according to the present invention, the wafer is fixed by sandwiching the wafer from above and below with the upper plate and the lower plate, the wafer is cut into a lattice shape through the upper plate, and further, the wafer is cut in a direction orthogonal to the previously cut direction through the lower plate. Is cut in a lattice shape, the wafer can be fixed and cut without using an adhesive tape, and the separation can be easily performed.

As a result, chips can be accurately separated from the wafer, and each chip can be reliably separated without damaging the chips, so that highly reliable supply of semiconductor chips has become possible.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings.

First, (a) to (e) of FIG. 1 are explanatory views of the processing steps of Embodiment 1 of the present invention, and FIG. 2 is a perspective view for explaining Embodiment 2.
(A) is a use state diagram, (b) is a carry state diagram, FIG. 3 is a diagram of the top plate of the second embodiment, (a) is a perspective view,
(B) is an enlarged view of a part B of (a), (c) is an enlarged view of a part C of (b), and FIG. 4 is a perspective view of a lower plate of the third embodiment.

In the figure, 11 is a wafer, 12 is a chip, 13a is an upper surface plate, 13b is a lower surface plate, 14 is a kerf, 15 is a stopper, 16 is a recess, 1
7 is a convex portion, 18a and 18b are alignment portions, 19 is a rubber sheet (a pressing portion for a chip), and 20 is a push-up portion.

Example 1 As shown in FIG. 1 (a), a wafer 11 is sandwiched from above and below by an upper plate 13a and a lower plate 13b made of a transparent acrylic resin plate or cardboard which is larger than the wafer.
Fix in the state of. Next, as shown in FIG. 1 (c), after accurate positioning, the wafer is cut into a lattice shape with a chip width using a dedicated cutter (not shown) via the upper plate 13a. The upper surface plate 13a is not cut off but leaves an edge, but the wafers inside are all cut off. Further, as shown in FIG. 1 (d), the wafer is fixed upside down with the wafer fixed.
The wafer is cut into a lattice shape in a direction perpendicular to the direction cut earlier through the lower plate 13b. Also in the case of the lower surface plate 13b, the edges are left without cutting all, and the wafers inside are all cut off. Subsequently, as shown in FIG. 1 (e), the plate is removed and chips 12 are separated.

In this way, the upper plate 13a and the lower plate 13b are not cut, and only the wafer 11 sandwiched therebetween can be cut into rectangular chips 12 without fail. Since the wafer 11 is sandwiched and fixed from above and below by the plates (13a, 13b), it does not shift when the wafer 11 is cut, and when the chips 12 are separated, it can be easily taken out just by separating the upper and lower plates. become. Further, since the wafer can be fixed and full cut can be performed without using an adhesive tape as in the related art, various problems due to the adhesive tape do not occur.

Example 2 In Example 2, as shown in each of FIGS. 2A and 2B, the upper surface plate 13a and the lower surface plate 13b used had a cutting groove 14 for cutting a wafer in advance. Since the incision 14 is accurately cut in accordance with the position and size of the chip, positioning can be performed only by aligning the cutter with the incision 14.

As shown in FIG. 2 (a), a concave portion 16 is formed in the lower surface plate 13b so as to conform to the shape of the wafer. The wafer is fixed by inserting the convex portion 17 of 13a. The upper plate 13a, the lower plate 13b, and the wafer are aligned by the alignment units 18a, 18b. FIG. 2 (b) shows a state in which the upper plate 13a and the lower plate 13b are carried together, and the two plates are securely and easily carried by fixing them with the stoppers 15 at about four places. Is made possible.

FIG. 3 shows that, if a plate is pressed directly against the element forming surface of the wafer, the surface may be damaged. Therefore, a flexible rubber sheet 19 or the like is provided on the plate (here, the upper plate 13a) in contact with the wafer surface. It is protected by sandwiching it. FIG. 3B is an enlarged view of a portion B of the upper surface plate 13a in FIG. 3A.
It is. It can be seen that the kerf 14 is cut according to the width of the chip. FIG. 3C is an enlarged view of a portion C in FIG. A rubber sheet 19 is adhered in a rectangular shape around a plate portion corresponding to a holding portion of each chip. For this reason, the surface of the chip is protected, so that scratches can be prevented from occurring, and the wafer can be prevented from being displaced by friction of the rubber sheet.

Third Embodiment As shown in FIG. 4, when the wafer 11 is cut into chips 12 and the upper plate (not shown) is removed, the chips 12 may adhere to the upper plate. A hole for suction may be formed in a portion corresponding to the above, and the upper plate may be removed after vacuuming.

〔The invention's effect〕

As described above, according to the present invention, semiconductor chips formed on a wafer can be accurately separated,
The chips can be reliably separated without damaging each chip.

[Brief description of the drawings]

1 (a) to 1 (e) are explanatory views of processing steps according to Embodiment 1 of the present invention, FIG. 2 is a perspective view illustrating Embodiment 2, and FIG. FIG. 3 is a diagram of the top plate of the second embodiment, FIG. 3 (a) is a perspective view, FIG. 3 (b) is an enlarged view of a portion B of FIG. 3 (a), and FIG. 3 (c) is a portion C of FIG. 4 is an enlarged view, FIG. 4 is a perspective view of a lower plate of the third embodiment, FIGS. 5 (a) and (b) are explanatory views of a conventional wafer processing method, and FIGS. 6 (a), (b) and (c) are conventional. FIG. 4 is a cross-sectional view of a wafer showing a problem of (1). In the figure, 11 is a wafer, 12 is a chip, 13a is an upper plate, 13b is a lower plate,
14 is a kerf, 15 is a stopper, 16 is a concave, 17 is a convex, 18a, 18b
Denotes a positioning portion, 19 denotes a rubber sheet (a pressing portion for a chip), and 20 denotes a push-up portion.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshiro Koya 1015 Uedanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Teruyuki Iwata 5950 Fueda, Iriki-cho, Satsuma-gun, Kagoshima Kyushu Fujitsu Limited Inside the electronics (72) Inventor Toshimitsu Kosaka 1-2-1 Nishigaoka, Murata-cho, Murata-cho, Shibata-gun, Miyagi 1 Fujitsu Miyagi Electronics Co., Ltd.

Claims (1)

(57) [Claims] 1. A wafer processing method for cutting a wafer (11) into rectangular chips (12), wherein the wafer (11) is vertically cut from an upper plate (13a) and a lower plate (1).
3b) sandwiching and fixing the wafer; cutting the wafer into a grid via the upper plate (13a); further cutting the wafer in a direction orthogonal to the direction previously cut via the lower plate (13b). Cutting the wafer into a lattice.